Device and method for reel-to-reel laser reflow

ABSTRACT

The present invention relates to a reel-to-reel layer reflow method, which emits a uniformized laser beam, which can easily adjust the emission area, and which is for the purpose of improving productivity. An embodiment of the present invention provides a reel-to-reel layer reflow method comprising the steps of: a) transferring a substrate, which has been wound in a roll type, to one side while unwinding the same; b) forming a solder portion on the substrate; c) seating an emission target element on the solder portion and seating a non-emission target element on the substrate; d) surface-emitting a laser beam to the solder portion, on which the emission target element is seated, such that the emission target element is attached to the substrate; e) inspecting the substrate structure manufactured through said step d); and f) winding the substrate structure in a roll type.

CROSS REFERENCE TO RELATED APPLICATION

This present application is a national stage filing under 35 U.S.C § 371of PCT application number PCT/KR2017/006039 filed on Jun. 9, 2017 whichis based upon and claims the benefit of priority to Korean PatentApplication No. 10-2016-0072647 filed on Jun. 10, 2016 in the KoreanIntellectual Property Office. The disclosures of the above-listedapplications are hereby incorporated by reference herein in theirentirety.

TECHNICAL FIELD

Exemplary embodiments according to the invention relate to a device andmethod for reel-to-reel laser reflow.

BACKGROUND ART

A reflow process, in general, is performed to fix a semiconductorelement to a substrate. A mass reflow process includes seating asubstrate attached with a solder material on a conveyor belt, and by theconveyor belt, passing the substrate through a heating section providedwith an infrared heater or a ceramic heater. The infrared heater orceramic heater is mounted above and below the conveyor belt, and appliesheat to the solder material on the substrate to thereby attach asemiconductor element to the substrate. Since the mass reflow processrequires at least minutes to apply heat to the solder material using theinfrared heater or ceramic heater to combine the semiconductor elementto the substrate, such a scheme is not economical.

In recent times, a thin substrate structure including a substratecombined with a semiconductor element is used, including the use of afilm substrate, wherein a semiconductor element, such as a passiveelement, an integrated circuit (IC) element, is attached to a singlesubstrate. During the mass reflow process, the film substrate mayexperience thermal deformation (expansion and damage), such that the ICelement after undergoing the mass reflow process may have difficultybeing bonded on a predetermined position in a normal manner. Moreover,the mass reflow process may cause an air gap between a lower surface ofthe substrate and an upper surface of the conveyor belt. Thus, part ofthe heat emitted from the infrared heater is trapped in the air gap andremains therein, thereby causing thermal deformation in the substrate.

Korean Patent Application No. 2012-0037543 discloses a reflow device andmethod using a laser module. According to Korean Patent Application No.2012-0037543, a print circuit board formed with a solder ball ispreheated using an infrared (IR) lamp, and a lase square beam is emittedto the preheated board to melt the solder ball. The reflow device andmethod using a laser module in Korean Patent Application No.2012-0037543 cannot adjust the emission area of a laser beam, and thus,in the case of attaching a semiconductor element, such as a passiveelement, an IC element, to a single substrate, the IC element would bethermally impacted, thereby causing defects.

China Patent Application No. 101533482 discloses a chip bonding methodusing laser. According to China Patent Application No. 101533482, a cutface of an anisotropic conductive film is bonded to a recessed portionusing laser after loading a chip on the recessed portion in a substrate,and bonds the chip to the substrate using laser. However, China PatentApplication No. 101533482 does not disclose any feature of adjusting theemission area of a laser beam.

U.S. Patent Application No. 2003-0084563 discloses a bonding deviceincluding a loading reel and an unloading reel for transferring aprocessed article. However, U.S. Patent Application No. 2003-0084563also does not disclose any feature of adjusting the emission area of alaser beam.

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

An objective of the invention is to provide a reel-to-reel laser reflowtechnique for bonding an emission target element to a substrate byemitting a uniformized laser beam to the substrate.

Additionally, another objective of the invention is to provide areel-to-reel laser reflow technique capable of adjusting the shape andsize of the emission area of the uniformized laser beam according to theshape and position of the emission target element.

The other objectives of the invention will be more clearly understoodfrom the following detailed description of exemplary embodiments.

Means for Solving Problem

In order to achieve the aforementioned objectives, a reel-to-reel laserreflow method according to an exemplary embodiment of the inventionincludes a) transferring a substrate, which has been wound in a rolltype, to one side while unwinding the substrate, b) forming a solderportion on the substrate, c) seating an emission target element on thesolder portion and seating a non-emission target element on thesubstrate, d) emitting a laser square beam to the solder portion, onwhich the emission target element is seated, such that the emissiontarget element is attached to the substrate, e) inspecting the substratestructure manufactured through the step d), and f) winding the substratestructure in a roll type.

According to another exemplary embodiment of the invention, areel-to-reel laser reflow device includes a first reel to unwind asubstrate wound in a roll type, a transfer unit to transfer thesubstrate unwound by the first reel, a second reel to control a movementof the substrate, a solder forming unit to form a solder portion on thesubstrate, an element seating unit to seat an emission target element onthe solder portion and seat a non-emission target element on thesubstrate, an optical unit to adjust an emission area of a laser beam sothat a uniformized laser beam is emitted only to the emission targetelement seated on the solder portion, an inspection unit to inspect thesubstrate structure attached with the emission target element seated onthe solder portion; and a third reel to wind the substrate structurethat has passed through the inspection unit.

Effect of the Invention

According one or more exemplary embodiments of the invention, thereel-to-reel laser reflow method can readily adjust the shape and sizeof the emission area of the laser beam according to the shape andposition of the emission target element.

Furthermore, according one or more exemplary embodiments of theinvention, the reel-to-reel laser reflow method can attach an emissiontarget element to a substrate by emitting a laser beam to the emissiontarget element for one to two seconds, such that the operation time isreduced compared to a conventional mass reflow process.

Additionally, as no air gap is generated between a conveyor and asubstrate, it is possible to prevent damage that may occur to thesubstrate due to residual heat energy.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow chart illustrating a reel-to-reel laser reflow methodaccording to an exemplary embodiment of the invention.

FIG. 2 is a view illustrating an example of an overall process flow ofthe reel-to-reel laser reflow method according to an exemplaryembodiment of the invention.

FIG. 3 is a view illustrating an example of the feature of bringing asubstrate on which an emission target element and a non-emission targetelement are seated in contact with a conveyor.

FIG. 4 is a flow chart illustrating the step of attaching the emissiontarget element to the substrate.

FIG. 5 is a view illustrating an example of the feature of attaching theemission target element to the substrate.

FIGS. 6 and 7 are views illustrating examples of a first cylindricallens and a second cylindrical lens.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1 and 2, a reel-to-reel laser reflow method accordingto an exemplary embodiment of the invention includes the step oftransferring a substrate, which has been wound in a roll type, to oneside while unwinding the same (S110). A substrate (210) may comprise aflexible print circuit board (FPCB) in the shape of a roll. Thesubstrate (210) may have a thickness in the range of 0.03 mm to 0.15 mm.A first reel (220 a) unwinds the substrate (210), and the substrate(210) unwound by the first reel (220 a) is transferred to a third reel(220 c).

In FIG. 1, subsequent to S110, the reel-to-reel laser reflow methodaccording to an exemplary embodiment of the invention includes the stepof forming a solder portion (S) on the substrate (210) (S120). Thesolder portion (S) may include a solder ball, a solder paste, etc. S120may include the step of screen-printing a solder paste on the substrate(210). In section B1 in FIG. 2, the screen-printing step may beperformed on the substrate (210).

Referring to FIG. 1, the reel-to-reel laser reflow method according toan exemplary embodiment of the invention includes the step of seating anemission target element (211) on the solder portion (S) and seating anon-emission target element (212) on the substrate (S140). The emissiontarget element (211) refers to a semiconductor element that is attachedto the substrate (210) by emitting a laser beam, and for example, mayinclude a passive element. The non-emission target element (212) refersto a semiconductor element that is attached to the substrate (210) byother means, because the non-emission target element (212) mayexperience thermal deformation due to the laser beam. The non-emissiontarget element (212) may include an integrated circuit (IC) element. TheIC element includes a touch IC, and a driver IC. The emission targetelement (211) and the non-emission target element (212) may be seated onthe substrate (210) by an element seating unit (not shown) in section B2in FIG. 2.

Referring to FIG. 1, the reel-to-reel laser reflow method according toan exemplary embodiment of the invention may further include the step ofcontacting a lower surface of the substrate (210) with an upper surfaceof a conveyor (231) for transferring the substrate (210), prior to orsubsequent to S140. In the case where the substrate (210) is not incontact with the conveyor (231), an air gap may exist between the lowersurface of the substrate (210) and the upper surface of the conveyor(231).

By way of example, a second reel (220 b) shown in FIGS. 3 and 5 ismounted on opposite sides of the conveyor (231) in section B3 in FIG. 2,and is used to control the movement of the substrate (210). The secondreel (220 b) operates in conjunction with a transfer module (232), whichwill be described below, to move or suspend the substrate (210) so as toallow a laser beam to be sequentially emitted to the emission targetelement (211). The second reel (220 b) may operate in conjunction with afirst reel (220 a) and a third reel (220 c) to move in the same manneras the first and third reels. As the substrate (210) is pressed by thesecond reel (220 b) at the opposite sides of the conveyor (231), thesubstrate (210) and the conveyor (231) are not in close contact with oneanother, such that an air gap may be generated between the substrate(210) and the conveyor (231). When a laser beam is emitted to the solderportion (S), part of the energy of the laser beam that has passedthrough the substrate (210) may not fully pass through the substrate(210) and remains in the air gap. In such case, the substrate (210) mayexperience thermal deformation due to the residual energy.

In S130 in FIG. 1, the substrate (210) may be transferred to an emissionposition of the laser beam by the transfer unit (230), with thesubstrate (210) contacting the conveyor (231). Referring to FIG. 3, thetransfer unit (230) includes a conveyor (231) which may comprise thesubstrate (210) seated on an upper surface thereof and a transfer module(232) to feed a driving force to the second reel (220 b) to move thesubstrate (210).

The conveyor (231) may refer to a body of the transfer unit (230) onwhich the substrate (210) is seated, and which transfers the substrate(210) to emission position of the laser beam. The transfer unit (230)may further include a vacuum module (233) to feed a vacuum pressure toallow an upper surface of the conveyor (231) to contact a lower surfaceof the substrate (210). The vacuum module (233) may be connected to theconveyor (231) to feed the vacuum pressure for allowing the lowersurface of the substrate (210) to contact the conveyor (231). Theconveyor (231) may include a porous vacuum chuck made of a ceramicmaterial. The conveyor (231) including a porous vacuum chuck may includea plurality of minute cracks, and therefore, when the interior of theconveyor (231) is in a vacuum state by the vacuum module (233), the airabove the upper surface of the conveyor (231) may pass through theinterior of the conveyor (231) to move downwards. By this flow of air,the substrate (210) may be brought in closer contact with the uppersurface of the conveyor (231).

During manufacturing, the substrate (210) may experience deformationssuch as warpage. Thus, when the substrate (210) is seated on theconveyor (231), part of a lower surface of the substrate (210) that isdeformed may not be in full contact with the conveyor (231). A pressurecontacting unit (240) may be mounted to allow the substrate (210) tocontact the conveyor (231). The pressure contacting unit (240) includesa pressure rod (241) and a pressure control module (242). The pressurerod (241) may include a plurality of pressure rods above the conveyor(231), and may have a shape of a vertically extending cylinder. Theshape of the pressure rod (241) is not limited to such an example. Thepressure rod (241) may have any shape that allows the substrate (210) tocontact the conveyor (231) by temporarily applying pressure to an uppersurface of the substrate (210). The pressure control module (242) maymove the pressure rod (241) in a horizontal direction to position thepressure rod (241) on an upper side of the substrate (210) where thesubstrate (210) and the conveyor (231) are not in contact with oneanother. The pressure control module (242) may be connected to thepressure rod (241) to move the pressure rod (241) to a lower side of thesubstrate (210). The pressure control module (242) may bring thesubstrate (210) to contact the conveyor (231) and then move the pressurerod (241) to the upper side. The pressure control module (242) may applypressure to the upper surface of the substrate (210) and may applypressure to a part of the substrate (210) where the solder portion (S)is not present.

In the case where a laser beam is emitted to the solder portion (S),with the upper surface of the substrate (210) contacting the uppersurface of the conveyor (231), damage to the substrate (210) due toresidual energy may be prevented as there would be no air gap generatedbetween the conveyor (231) and the substrate (210).

The transfer unit (230) may further include a heater module (234) and acooling module (235) provided in the conveyor (231). The heater module(234) and the cooling module (235) may adjust the temperature of theconveyor (231) to thereby effectively prevent the generation of thermaldeformation to the substrate (210). The heater module (234) may comprisean infrared heater, and the cooling module (235) may include a coolerhaving a coolant. The cooling module (235) may also include athermoelectric cooler.

The transfer module (232) moves the conveyor (231) to sequentiallyposition the substrate (210) on emission positions. The transfer module(232) may control the second reel (220 b) to allow the substrate (210)positioned on an emission position to linger for as long as apredetermined period of time in which a laser beam is emitted to thesubstrate (210).

Referring to FIGS. 1 and 5, the reel-to-reel laser reflow methodaccording to an exemplary embodiment of the invention includes the stepof emitting a square laser beam to the solder portion (S) on which anemission target element (211) is seated to thereby attach the emissiontarget element (211) to the substrate (210) (S160). S160 may be carriedout in section B3 in FIG. 2. In FIG. 4, S160 includes the step ofuniformizing the energy of the laser beam (S161). In general, a laserbeam has a Gaussian distribution wherein the energy of the laser beamdecreases as being away from the center of the emission area.Accordingly, when a laser beam having a Gaussian function distributionis emitted to the solder portion (S) on which the emission targetelement (211) is seated, a central portion of the emission area mayexperience thermal deformation due to an excessive heat energy, and dueto lack of energy necessary for reflow at an edge portion of theemission area, the emission target element (211) may not be secured tothe substrate (210). Therefore, in S161, uniformization of energy may beperformed in the emission area where the laser beam is emitted.Hereinafter, a process of uniformizing the energy of the laser beamhaving a Gaussian function distribution will be described.

According to an exemplary embodiment of the invention, a beam shaper(250) (see FIG. 5) is used to convert a laser beam in a Gaussian type toa surface light source having a uniformized energy distribution.Examples of the beam shaper are disclosed in Korean Patent PublicationNo. 10-1017848. For example, the beam shaper may include an opticalfiber and a square light pipe for forming a uniformized square laserbeam.

In FIG. 4, subsequent to S161, the step of adjusting the emission areaof the laser beam (S161) may be carried out. The size and the shape ofthe emission target element (211) secured to the substrate (210) mayvary depending on a semi-finished product. The substrate (210) mayinclude a non-emission target element (212) seated thereon, in additionto the emission target element (211), and the non-emission targetelement (212) may easily experience thermal deformation due to theenergy of the laser beam. Thus, in S162, in order to emit a laser beamthat corresponds to the shape and size of the emission target element(211) seated on the substrate (210), an emission area of the laser beammay be adjusted. An emission area may refer to a surface area to which alaser beam is emitted, when radiating the laser beam to the emissiontarget element (211). Hereinafter, a process of adjusting the emissionarea of the laser beam using an optical unit (260) will be described.

Referring to FIG. 5, the optical unit (260) may include a convex lens(261), a circumferential lens (262) and a focusing lens (265). Theoptical unit (260) is disposed at an outlet side of the beam shaper(250), and may adjust an emission area when a laser beam is emitted to asolder portion (S) on which the emission target element (211) ispositioned. The convex lens (261) may be mounted adjacent to the outletside of the beam shaper (250) that uniformizes the laser beam tocondense the laser beam that is being surface-emitted. The laser beammay be dispersed when passing through the outlet side of the beam shaper(250). Thus, the convex lens (261) may condense the uniformized beam soas not to be dispersed, and may transmit the condensed laser beam to thecircumferential lens (262). An emission area of the laser beam condensedby the convex lens (261) may have an identical shape as the shape of acore (251) through which the laser beam passes for uniformization. Theemission area of the laser beam that has passed through the convex lens(261) may form a first emission area (A1). The convex lens (261) may besubstituted with any lens capable of condensing a laser beam dispersedat an outlet side of the beam shaper (250).

The circumferential lens (262) includes a first cylindrical lens (263)and a second cylindrical lens (264), and may adjust the emission area ofthe laser beam that has passed through the convex lens (261) to have apredetermined shape. The first cylindrical lens (263) may adjust alength of the laser beam that has passed through the convex lens (261)in a first axis direction. The first cylindrical lens (263) may bemounted in the shape of a vertically rising cylinder that is cut along atransverse axis. The first cylindrical lens (263) may be provided belowthe convex lens (261), with a convex face of the first cylindrical lens(263) facing upwards. An emission area of the laser beam that passesthrough the first cylindrical lens (263) may be formed to have a lengthin the first axis direction decreasing. As the length of the laser beamthat has passed through the first cylindrical lens (263) in the firstaxis direction decreases, the emission area may be transitioned from thefirst emission area (A1) to a second emission area (A2).

The second cylindrical lens (264) may adjust a length of the laser beamthat has passed through the first cylindrical lens (263) in a secondaxis direction. The length of the laser beam in the second axisdirection is at right angles with the length of the laser beam in thefirst axis direction. The second cylindrical lens (264) may be formed tohave an identical shape as the shape of the first cylindrical lens(263). The second cylindrical lens (264) may be provided below the firstcylindrical lens (263), with a convex face of the second cylindricallens (264) facing upwards. The second cylindrical lens (264) may beprovided at right angles with the first cylindrical lens (263). Anemission area of the laser beam that passes through the secondcylindrical lens (264) may be formed to have a length in the second axisdirection decreasing. As the length of the laser beam that has passedthrough the second cylindrical lens (264) in the second axis directiondecreases, the emission area may be transitioned from the secondemission area (A2) to a third emission area (A3).

The first cylindrical lens (263) and the second cylindrical lens (264)may readily adjust the shape of the emission area of the laser. Thefirst cylindrical lens (263) and the second cylindrical lens (264) arenot limited to an example, and may comprise any elements capable ofreadily adjusting the length of the emission area in the first axisdirection and the length of the emission area in the second axisdirection. The first cylindrical lens (263) and the second cylindricallens (264) may be disposed to allow a convex face thereof to facedownwards, and a lens with a convex upper face may be mounted at thepositions of the first cylindrical lens (263) and the second cylindricallens (264). The emission area of the laser beam may be adjusted toincrease the length in the first axis direction and the length in thesecond axis direction. The first cylindrical lens (263) and the secondcylindrical lens (264) may comprise any examples capable of adjusting alength ratio between the transverse length and the longitudinal lengthof the emission area by adjusting the length of the emission area of thelaser beam in the first axis direction and the length of the emissionarea of the laser in the second axis direction.

The first cylindrical lens (263) and the second cylindrical lens (264)may switch their positions. Specifically, by allowing the laser that haspassed through the convex lens (261) to transmit the second cylindricallens (264) before transmitting the first cylindrical lens (263, thelength of the emission area in the first axis direction may be adjustedafter the length of the emission area in the second axis direction isadjusted.

The focusing lens (265) controls the emission area of the laser that haspassed through the circumferential lens (262) to have a predeterminedsurface area. The focusing lens (265) may increase or decrease thesurface area of the emission area, while maintaining the shape of theemission area formed by the circumferential lens (262). The focusinglens (265) may increase or decrease the surface area of the emissionarea, in a state where the shape of the emission area is maintained bymaintaining a ratio of the length in the second axis direction to thelength in the first axis direction in the emission area formed by thecircumferential lens (262). By expanding the third emission area (A3),which is the emission area of the laser beam that has passed through thesecond cylindrical lens (264), using the focusing lens (265), the thirdemission area (A3) may have a surface area of a fourth emission area(A4). The focusing lens (265) may also reduce the surface area of thethird emission area (A3). The focusing lens (265) may be provided as areplaceable element.

In FIG. 5, the optical unit (260) may further include a lifting module(266). The lifting module (266) may adjust an emission area of a laserbeam by lifting or lowering the first cylindrical lens (263), the secondcylindrical lens (264) and the focusing lens (265). The lifting module(266) may adjust the length of the emission area in the first axisdirection when the first emission area (A1) is transitioned into thesecond emission area (A2) by lifting or lowering the first cylindricallens (263). As the first cylindrical lens (263) is lifted higher, thelength of the second emission area (A2) in the first axis directionconsiderably decreases, and as the first cylindrical lens (263) islowered, the length of the second emission area (A2) in the second axisdirection decreases slightly. The lifting module (266) may adjust thelength of the emission area in the second axis direction when the secondemission area (A2) is transitioned into the third emission area (A3) bylifting or lowering the second cylindrical lens (264). In transition ofthe third emission area (A3) into a fourth emission area (A4), thelifting module (266) may adjust the surface area of the fourth emissionarea (A4) by lifting or lowering the focusing lens (265). In a similarmanner, the length of the emission area in the second axis direction maybe adjusted by lifting or lowering the second cylindrical lens (264),and the surface area of the emission area may be adjusted by lifting orlowering the focusing lens (265).

In FIG. 4, subsequent to S162, the step of securing the emission targetelement (211) to the substrate (210) by reflowing the solder portion (S)positioned within the emission area by a lase beam is performed (S163).In S162, The laser beam uniformized in S161 passes through the opticalunit (260) thereby adjusting the emission area, and the laser beam withthe adjusted emission area is emitted to the solder portion (S) on whichthe emission target element (211) is seated in S163, thereby securingthe substrate (210) and the emission target element (211). The laserbeam emitted to the emission target element (211) passes through theemission target element (211) and the substrate (210), and reflows thesolder portion (S). When the solder portion (S) is reflowed, theemission target element (211) and the substrate (210) are attached toone another, such that the substrate (210) and the emission targetelement (211) are electrically connected.

The reel-to-reel laser reflow method according to an exemplaryembodiment of the invention may attach the emission target element (211)to the substrate (210) by radiating the laser beam for one to twoseconds. Consequently, the reel-to-reel laser reflow method according toan exemplary embodiment of the invention can manufacture a substratestructure (280) at a higher speed than prior art, thus increasingproductivity.

Conventionally, an emission target element (211) and a non-emissiontarget element (212) need to be separately attached to two differentsubstrates (210), and then the substrate attached with the emissiontarget element (211) and the substrate attached with the non-emissiontarget element (212) are combined, and therefore, a substrate structure(280) would have a great thickness and accordingly, a semi-finishedproduct would also have a great thickness. However, according to anexemplary embodiment of the invention, the reel-to-reel laser reflowmethod includes attaching the emission target element (211) and thenon-emission target element (212) to a single substrate (210), and thus,the thickness of the substrate structure (280) can be reduced.

In S163, at least one measurement location may be set within an emissionarea. A temperature of a solder portion (S) positioned at themeasurement location may be measured in real time. For example, thetemperature of the solder portion (S) may be measured in real time by atemperature measurement unit (270) disposed above the transfer unit(230). The temperature measurement unit (270) may include an infraredcamera or a heat detection camera, etc. The temperature measurement unit(270) may control the level of energy of a laser beam so that a solderportion (S) positioned at the measurement location maintains apredetermined normal range of temperature. In the case where thetemperature of the solder portion (S) positioned at the measurementlocation deviates the predetermined normal range of temperature, anotification is sent to a user to inform the occurrence of defect inorder to reduce a defect rate of semi-finished products.

In FIG. 1, the step of attaching the non-emission target element (212)to the substrate (210) may further be performed (S150), prior to orsubsequent to S160. In a conventional mass reflow process, in the caseof emitting a laser beam to the substrate (210) in a state where thenon-emission target element (212) is attached to the substrate (210),thermal deformation may occur in the non-emission target element (212).Moreover, in the case of attaching the non-emission target element (212)to the substrate (210) after attaching the emission target element (211)to the substrate (210), a problem would arise due to the thermaldeformation on the substrate (210) as the non-emission target element(212) is attached to the substrate (210) without having an optimizedpitch. However, since the reel-to-reel laser reflow method according toan exemplary embodiment of the invention can radiate a laser beam onlyto a position of the emission target element (211), whether the laserbeam is emitted to the emission target element (211) prior to orsubsequent to the attachment of the non-emission target element (212) tothe substrate (210), no defects would occur. Therefore, S150 may beperformed by an additional bonding device (not shown) prior to orsubsequent to S160 depending on the conditions. Also, the non-emissiontarget element (212) may be attached to the substrate (210)simultaneously with the emission target element (211) being attached tothe substrate (210).

In FIG. 1, the reel-to-reel laser reflow method according to anexemplary embodiment of the invention may perform the step of inspectingthe substrate structure (280) manufactured through S160 (S170). Thesubstrate structure (280) includes a substrate (210), an emission targetelement (211) attached to the substrate (210) and a non-emission targetelement (212). The substrate structure (280) may be inspected to detectwhether there is a thermal deformation upon emission of the laser beam,and to determine whether the emission target element (211) and thenon-emission target element (212) attached to the substrate structure(280) are attached to predetermined positions. Furthermore, marking maybe performed on a substrate structure (280) that is determined to have adefect. The marked substrate structure (280) may be excluded from asubsequent process.

In FIG. 1, subsequent to S170, the reel-to-reel laser reflow methodaccording to an exemplary embodiment of the invention may perform thestep of winding the substrate structure in a roll type (S180). A thirdreel (220 c) is mounted downstream of section B4 in FIG. 2. The thirdreel (220 c) may wind the substrate structure (280) in a roll type. Thereel-to-reel laser reflow method according to an exemplary embodiment ofthe invention performs a series of steps from the first reel (220 a) tothe third reel (220 c), to finally produce the substrate structure (280)in a roll type, thereby reducing a process time and facilitatingtransport, providing an economically efficient method. FIGS. 6 and 7 areviews illustrating examples of a first cylindrical lens and a secondcylindrical lens.

DRAWING REFERENCE NUMERALS

-   -   210: substrate    -   211: emission target element    -   212: non-emission target element    -   220 a: first reel    -   220 b: second reel    -   220 c: third reel    -   230: transfer unit    -   231: conveyor    -   232: transfer module    -   233: vacuum module    -   234: heater module    -   235: heater module    -   240: pressure contacting unit    -   241: pressure rod    -   242: pressure control module    -   250: beam shaper    -   260: optical unit    -   261: convex lens    -   262: circumferential lens    -   263: first cylindrical lens    -   264: second cylindrical lens    -   265: focusing lens    -   266: lifting module    -   270: temperature measurement unit    -   280: substrate structure

MODE(S) FOR CARRYING OUT THE INVENTION

As described in the foregoing, modes for carrying out the invention areprovided in an optimal way to carry out the invention.

INDUSTRIAL APPLICABILITY

Description according to the present application is applicable to alaser reflow device.

1. A reel-to-reel laser reflow method, the method comprising: a)transferring a substrate, which has been wound in a roll type, to oneside while unwinding the substrate; b) forming a solder portion on thesubstrate; c) seating an emission target element on the solder portionand seating a non-emission target element on the substrate; d)surface-emitting a laser beam to the solder portion, on which theemission target element is seated, such that the emission target elementis attached to the substrate; e) inspecting the substrate structuremanufactured through the step d); and f) winding the substrate structurein a roll type.
 2. The method according to claim 1, wherein the step b)comprises forming a solder portion on the substrate by screen printing asolder paste on the substrate.
 3. The method according to claim 1,further comprising contacting a lower surface of the substrate with anupper surface of a conveyor for transferring the substrate, prior to orsubsequent to the step c).
 4. The method according to claim 1, furthercomprising attaching the non-emission target element to the substrate,prior to or subsequent to the step d).
 5. The method according to claim1, wherein the step d) comprises: d1) uniformizing the energy of thelaser beam;□ d2) adjusting an emission area of the laser beam; and □d3)reflowing the solder portion positioned within the emission area by thelaser beam to thereby secure the emission target element to thesubstrate.
 6. A reel-to-reel laser reflow device, the device comprising:a first reel to unwind a substrate wound in a roll type; a transfer unitto transfer the substrate unwound by the first reel; a pressurecontacting unit to apply pressure to the substrate to bring thesubstrate to contact the transfer unit; a second reel to control amovement of the substrate; a solder forming unit to form a solderportion on the substrate; an element seating unit to seat an emissiontarget element on the solder portion and seat a non-emission targetelement on the substrate; an optical unit to adjust an emission area ofa laser beam so that a uniformized laser beam is emitted only to theemission target element seated on the solder portion; an inspection unitto inspect the substrate structure attached with the emission targetelement seated on the solder portion; and a third reel to wind thesubstrate structure that has passed through the inspection unit.
 7. Thedevice according to claim 6, wherein the transfer unit comprises: aconveyor on which the substrate is seated; a transfer module to feed adriving force to the second reel to thereby move the substrate to oneside; and a vacuum module to feed a vacuum pressure to bring a lowersurface of the substrate in contact with an upper surface of theconveyor.
 8. The device according to claim 7, wherein the transfer unitfurther comprises a heater module and a cooling module for adjusting thetemperature of the conveyor.
 9. The device according to claim 6, whereinthe pressure contacting unit comprises: a pressure rod mounted above theconveyor; and a pressure control module to control the pressure rod tomove in longitudinal and transverse directions.
 10. The device accordingto claim 6, wherein the solder forming unit comprises a screen printerto screen-print a solder paste on the substrate.
 11. The deviceaccording to claim 6, wherein the optical unit comprises: a beam shaperto convert a laser beam in a Gaussian type emitted from a laser unit toa surface light source having a uniformized energy distribution; aconvex lens to condense the laser beam output from the beam shaper; afirst cylindrical lens to adjust a length of the laser beam that haspassed through the convex lens in a first axis direction; a secondcylindrical lens to adjust a length of the laser beam that has passedthrough the first cylindrical lens in a second axis direction; afocusing lens to allow the emission area of the laser beam that haspassed through the second cylindrical lens to have a predeterminedsurface area; and a lifting module to adjust the emission area of thelaser beam by lifting or lowering the first cylindrical lens, the secondcylindrical lens and the focusing lens individually.